A common problem in chemical reaction processes is how to achieve the proper hydrodynamics in the reactor to efficiently produce the desired products. The reactants need to be mixed so that the molecules of the reaction components come into contact with the other components in the reaction including catalysts. The presence of a gaseous reactant requires the increase of the surface area of the boundary between the gas and the liquid components to increase the efficiency of the reaction. Many processes require fine temperature control or added energy from an electromagnetic field. In some cases rapid temperature changes are desired though difficult to achieve due to the thermal inertia of the reaction components. Also, it is often difficult to ensure proper saturation of the reaction components by an electromagnetic field as the outermost portion of the mixture of reactants tends to be exposed to more radiation than the innermost portion.
Thin film reactors are known to overcome many of these issues however an improved thin film reactor is needed. For example, techniques are known for applying a catalyst to a surface for use as a thin film reactor to thereby provide improved contact with the process components. Such techniques include sol-gel or washcoating, which can be used to adhere a catalytically active coat onto the inner wall of a reactor. However, these coats tend to suffer from attrition and will inevitably deactivate with time. Further, there a number of patents in the art that attempt to address some of the above issues are described below.
U.S. Pat. No. 6,742,774 to Holl discloses a reactor that produces a gas-in-liquid emulsion for providing increased interfacial contact area between the liquid and the gas for-improved-reaction of the gas with the liquid, or more rapid solution or reaction of a gas in or with a liquid. Rotor and stator cylindrical members are mounted for rotation relative to one another and have opposing surfaces spaced to form an annular processing passage. The gap distance between the opposing surfaces and the relative rotation rate of the cylindrical members are such as to form a gas-in-liquid emulsion. Holl is thus directed to a process for mixing a gas and a liquid into an emulsion to increase the contact between the gaseous and liquid components rather than forming a thin film with a large surface area.
U.S. Pat. No. 6,512,131 to Best, et al. discloses a process for carrying out a multi-phase reaction in a continuously operated tube reactor with a liquid phase flowing downwards as a thin film in said tube reactor and components of a continuous gas flowing upward in said tube reactor are brought to material transfer, or reaction respectively. Best uses gas pressure modulation to maintain the thin film and thus does not rotate the tube to provide or maintain the thin film nature of the liquid phase of the reaction. Further, Best does not provide for the separation of multiple products in an integrated separation reservoir.
U.S. Pat. No. 4,675,137 to Umetsu discloses a method for producing a polyacetylene film by introducing acetylene gas into a vessel for storing Ziegler-Natta catalyst to polymerize the acetylene gas with the catalyst. Rotating the vessel coats the side wall with the catalyst. Thus, the acetylene gas introduced into the vessel is polymerized with the catalyst to produce the polyacetylene film. Umetsu's method is not a continuous process and the catalyst is not immobilized.
U.S. Pat. No. 4,353,874 to Keller, et al. discloses a rotary tube reactor, having at least one treatment line composed of tubes with individual sections having gas chambers that are sealed from each other. Each section has a gas outlet and adjacent sections are joined together by material passages. The reactor is used for thermal treatment. Keller relies on multiple tubes to transport reactants within the rotating tube and does not form a thin film on the inner surface of the rotating tube.
U.S. Pat. No. 4,335,079 to Vander Mey discloses an apparatus for a continuous process which comprises introducing a liquid onto a spherical rotating reaction surface as a thin film and rotating the reaction surface at a velocity such that the thin film is continuously moved toward the periphery of the reaction surface. Vander Mey divides the reaction surface into a plurality of areas and deposits within each area a controlled quantity of gas over the liquid film. A sub-atmospheric pressure is maintained while the temperature of the reaction surface is controlled. The reaction product moves to the periphery of the reaction surface by centrifugal action and the reaction product is continuously collected. Vander Mey is directed specifically toward reacting a thin film with a gas. Further, Vander Mey relies on a spherical reaction surface to move the film toward the product collection element and does not discuss the separation of multiple products.
U.S. Pat. No. 4,311,570 to Cowen, et al. discloses chemical processes using thin films of reactants carried out on the surface of a body rotating at high speed. The solid and insoluble liquid products are isolated by using centrifugal force to fling the products from the rim of the body into the surrounding atmosphere. Thus, Cowen relies on products that are solid, such as fibers or powders, or liquids that are incompatible with other products for separation. Further, Cowen requires that-at least part of the reaction surface of the reactor be inclined with respect to the axis of rotation.
Therefore, a reactor or thermal processor that utilizes a rotating tube to create a thin film of process components for a continuous reaction is desired. Further, a reactor or thermal processor that utilizes an improved separation means is desired.